With the trend toward the lighter and slimmer displays, including for portable display devices, e.g., notebook computers, mobile phones, and portable media players, and including for home display devices, e.g., TV sets and monitors, a variety of flat panel displays are being used. The flat panel display includes a display panel and may be classified, e.g., into a liquid crystal display, an organic electroluminescent display device, an electrophoretic display device, and the like, according to the kind of display panel.